ELNA 745 -, Руководство по обслуживанию

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1. Remove: Mains lead - Sewing foot - Machine base - Needle plate.
2. Make sure that there is no axial play on chain looper shaft "a" . If necessary, adjust with
stop collar inside shaft "g" in Fig.6 in page 11c.
3. Angular position of chain looper: Insert a new needle (No 90) in "L2" . Check height
and orientation of needle bar in page 5. Bring chain looper to its far right swing position.
Check distance from point of chain looper to chain needle with thickness of gauge. If
necessary, loosen screw
"c" just enough to adjust the chain looper arm "d" angularly to
obtain a clearnace of 1.5 to 1.8mm . Then tighten screw "c" .(Fig.1)
Note: At this step, an easy check of the chain looper timing can be done as follows:
Chain looper motion right to left and the needle bar stroke should start at the same time.
Turn the handwheel towards you, bring the chain looper eye from right to left motion
behind the cover hem needle eye
"L0" . Check if eye of chain looper matches with eye
of needle (eye to eye).(Fig.2) If not, recheck all the above adjustments and adjust
timing stroke with eccentric
"5" . See page 3a & 3b for the position of eccentric. The
eccentric "5" is used for both chain and lower looper timing. When adjusting this
timing, make sure that you also check the adjustment of lower looper stroke.
( See page 6 and 8 )
4. Clearance of chain looper: Bring point of looper - from right to left - behind the cover
hem needle "L2" , and check if clearance is less than 0.05mm . Then bring tip of looper
behind the cover hem needle "L0" , and check if clearance is less than 0.05m .(Fig.3)
5. Clearance of chain needle(s) guard: Turn handwheel towards you until coverhem needle(s)
approaches to chain needle guard as close as possible. At this time, the clearance between
coverhem needle(s) and chain needle guard should be less than 0.1 mm. (See Fig. 4). If
necessary, adjust the clearance with screw
"e" (See Fig. 4) and make sure that the gap
between chain needle guard and the tip of chain looper is set at 1.0
~
2.0 mm. (See Fig. 5).
Note: Make sure that the chain needle "L0" is correctly positioned behind the chain looper
in its motion left to right. The (L0) needle tip (motion down) should be positioned at
the beginning of the chain looper hump (back of chain looper). See chain looper
orbital motion on Fig.3.
11b
CHAIN LOOPER : ANGULAR POSITION - CLEARANCE - ORBITAL
TIMING - CLEARANCE OF CHAIN NEEDLES GUARD